Field of the Invention
The present invention relates to a technology relating to a microscope apparatus including an automatic focusing device, the automatic focusing device, and an automatic focusing method.
Description of the Related Art
An active automatic focusing device used for a microscope detects feeble reflected light generated due to reflection of automatic focusing light (hereinafter referred to as AF light) applied to a specimen, and detects a focusing state on the basis of a detection signal. Accordingly, feeble stray light that is not a problem in usual microscopic observation may become a factor that interferes with an appropriate focusing determination.
In the field of microscopes, various technologies have been proposed for suppressing an adverse effect of stray light on focusing determination. As an example, Japanese Laid-Open Patent Publication No. 2007-148161 describes a technology for restricting a range in which a focal position adjustment lens moves to a range in which stray light that has been specified as a result of measurement is not generated. In addition, Japanese Laid-Open Patent Publication No. 2012-212018 describes a technology for correcting a detection signal in accordance with an intensity of stray light that has been measured.